Texas Instruments TI-89 Manual Book page 140

Finding y(x) at a
Specified Point
Tip: You can also display
function coordinates by
tracing the function ( ...),
typing an x value, and
pressing ¸ .
Finding a Zero,
Minimum, or
Maximum within an
Interval
Tip: Typing x values is a
quick way to set bounds.
Finding the
Intersection of Two
Functions within an
Interval
1. From the Graph screen, press ‡ and select
2. Type the value, which must be a real value between
x
. The value can be an expression.
xmax
3. Press ¸.
The cursor moves to that
value on the first function
x
selected in the Y= Editor, and
its coordinates are displayed.
4. Press D or C to move the cursor between functions at the
entered value. The corresponding
x
Note: If you press A or B, the free-moving cursor appears. You
may not be able to move it back to the entered
1. From the Graph screen, press ‡ and select
4:Maximum .
2. As necessary, use D and C to select the applicable function.
3. Set the lower bound for
to the lower bound or type its
4. Press ¸. A 4 at the top of the screen marks the lower bound.
5. Set the upper bound, and
press ¸.
The cursor moves to the
solution, and its coordinates
are displayed.
1. From the Graph screen, press ‡ and select
2. Select the first function, using D or C as necessary, and press
¸. The cursor moves to the next graphed function.
3. Select the second function, and press ¸.
4. Set the lower bound for
to the lower bound or type its
5. Press ¸. A 4 at the top of the screen marks the lower bound.
6. Set the upper bound, and
press ¸.
The cursor moves to the
intersection, and its
coordinates are displayed.
1:Value
value is displayed.
y
2:Zero
. Either use A and B to move the cursor
x
value.
x
5:Intersection
. Either use A and B to move the cursor
x
value.
x
y2(x)=2xì7
Chapter 6: Basic Function Graphing
.
and
xmin
y1(x)=1.25xùcos(x)
value.
x
, , or
3:Minimum
.
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